Loosing the rear end if it pukes coolant at the wrong time. Making someone else wad up thier bike because you're dripping coolant. Ect... those are worst case.. 2nd worst is cross contamination and some sort of problem internally. But you'd see milky coolant.If I'm not seeing any fluid now what's the worst case scenario? I see fluid and get it taken care of? Bike overheats and I know I have an issue? Is there catastrophic consequences that aren't reversible?